Mold-releasing agent

ABSTRACT

Disclosed is a mold-releasing agent comprising, as active ingredients, a polyfluoroalkylphosphonic acid represented by the general formula: C n F 2n+1 (CH 2 CF 2 ) a (CF 2 CF 2 ) b (CH 2 CH 2 ) c P(O)(OH) 2  (n: an integer of 1 to 6, a: an integer of 1 to 4, b: an integer of 1 to 3, c: an integer of 1 to 3), or a salt thereof and a polyfluoroalkylphosphonic acid oxyalkylene ester represented by the general formula: C n F 2n+1 (CH 2 CF 2 ) a (CF 2 CF 2 ) b (CH 2 CH 2 ) c P(O)[O(RO) m R′] d (OH) 2-d  (RO: a C 2 -C 6  linear or branched oxyalkylene group, R′: a hydrogen atom, a C 1 -C 20  alkyl group, or aralkyl group, n: an integer of 1 to 6, a: an integer of 1 to 4, b: an integer of 1 to 3, c: an integer of 1 to 3, d: an integer of 1 or 2, m: an integer of 1 to 100). This mold-releasing agent comprises, as an active ingredient, a polyfluoroalkylphosphonic acid oxyalkylene ester having a perfluoroalkyl group containing 6 or less carbon atoms, which is said to have low bioaccumulation potential, but exhibits mold release performance equivalent to that of a mold-releasing agent comprising a compound having a perfluoroalkyl group containing 8 or more carbon atoms as an active ingredient.

TECHNICAL FIELD

The present invention relates to a mold-releasing agent. More particularly, the present invention relates to a mold-releasing agent having excellent film-forming properties and excellent mold releasability.

BACKGROUND ART

Currently, silicone oil, wax, talc, mica, tetrafluoroethylene resin, and other mold-releasing agents are used in the molding of polymeric materials, such as plastic materials and rubber materials, using molds. Although silicone oil, wax, etc., have excellent mold releasability, such mold-releasing agents are transferred to molded products, thereby impairing uniform coating properties, secondary processability, and other properties; in addition, durability is not sufficient. As for tetrafluoroethylene resin, the durability of mold release effect and secondary processability are satisfactory; however, it is necessary to perform bake treatment to form a film on the molding surface of a mold in the mold-release process, and the same treatment is required for reprocessing. Consequently, many processes are required.

In order to solve these defects, mold-releasing agents comprising a C₄-C₂₀ polyfluoroalkyl group-containing phosphate ester as one of their active ingredients are proposed (see Patent Documents 1 to 3). These mold-releasing agents exhibit excellent mold releasability and have a longer mold release life than conventional mold-releasing agents; however, due to the recent trend toward the more complicated shape of molded products, there is a demand for mold-releasing agents having much higher performance.

Meanwhile, polyfluoroalkyl phosphonates are also widely used as starting materials for the synthesis of mold-releasing agents. Compounds having a C₈-C₁₂ perfluoroalkyl group are most likely to develop mold release performance when used as mold-releasing agents. In particular, phosphonate compounds having a perfluorooctyl group and represented by the general formula:

CF₃(CF₂)₇CH₂CH₂P(O)(OC₂H₅)₂

are preferably used for this kind of application (see Patent Documents 4 to 7).

Incidentally, it is reported that phosphate or phosphonate compounds having a C₈-C₁₂ perfluoroalkyl group are biologically degraded in the environment and converted to compounds having relatively high bioaccumulation and environmental concentration, causing concerns for exposure during treatment processes, and for release or diffusion from waste, treated substrates, etc., into the environment. Moreover, compounds having a perfluoroalkyl group containing 14 or more carbon atoms are very difficult to handle because of their physical and chemical properties, and hence, such compounds are rarely used in practice.

Furthermore, as for phosphate or phosphonate compounds having a perfluoroalkyl group containing 8 or more carbon atoms, generation and mixing of perfluorooctanoic acids with high bioaccumulation potential is unavoidable during the production of these compounds. For these reasons, companies that produce such phosphate or phosphonate compounds have retreated from the production of the compounds or promoted the use of alternative compounds having a perfluoroalkyl group containing 6 or less carbon atoms.

However, compounds having a perfluoroalkyl group containing 6 or less carbon atoms cause a significant decrease in orientation on the surface of a treated substrate, and the melting point, glass transition point (Tg), etc., of the compounds are markedly lower than those of C₈ compounds. Accordingly, the compounds are highly influenced by their environmental conditions, such as temperature, humidity, stress, and contact with organic solvents. Consequently, the desired performance cannot be sufficiently achieved, and durability and other properties are affected.

PRIOR ART DOCUMENT Patent Document

-   Patent Document 1: JP-B-53-23270 -   Patent Document 2: JP-B-53-23271 -   Patent Document 3: JP-B-57-48035 -   Patent Document 4: JP-B-2-45572 -   Patent Document 5: JP-B-3-78244 -   Patent Document 6: JP-B-4-4923 -   Patent Document 7: JP-B-4-11366 -   Patent Document 8: WO 2007/105633 A1

OUTLINE OF THE INVENTION Problem to be Solved by the Invention

An object of the present invention is to provide a mold-releasing agent comprising, as an active ingredient, a polyfluoroalkylphosphonic acid ester having a perfluoroalkyl group containing 6 or less carbon atoms, which is said to have low bioaccumulation potential, and mold release performance equivalent to that of a compound having a perfluoroalkyl group containing 8 or more carbon atoms.

Means for Solving the Problem

The object of the present invention can be accomplished by a mold-releasing agent comprising, as active ingredients, a polyfluoroalkylphosphonic acid represented by the general formula:

C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(C)P(O)(OH)₂  [I]

wherein n is an integer of 1 to 6, a is an integer of 1 to 4, b is an integer of 1 to 3, and c is an integer of 1 to 3, or a salt thereof and a polyfluoroalkylphosphonic acid oxyalkylene ester represented by the general formula:

C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)[O(RO)_(m)R′]_(d)(OH)_(2-d)  [XI]

wherein RO is a linear or branched oxyalkylene group having 2 to 6 carbon atoms, R′ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or aralkyl group, n is an integer of 1 to 6, a is an integer of 1 to 4, b is an integer of 1 to 3, c is an integer of 1 to 3, d is an integer of 1 or 2, and m is an integer of 1 to 100.

Effect of the Invention

When released into the environment, the polyfluoroalkylphosphonic acid (salt) and oxyalkylene ester thereof, as an active ingredient of a mold-releasing agent of the present invention, undergoes HF-elimination in the —CH₂CF₂— bonding site of the molecule, and a double bond is formed. The result is then subjected to ozone decomposition etc. to have a structure that is easily decomposed into a compound with low environmental concentration and low bioaccumulation potential. Moreover, the polyfluoroalkylphosphonic acid oxyalkylene ester does not produce environmental loading substances (e.g., perfluoroalkyl carboxylic acids having 8 or more carbon atoms) in the production process thereof.

A mold-releasing agent comprising the polyfluoroalkylphosphonic acid (salt) and oxyalkylene ester thereof as an active ingredient exhibits effective mold release performance, even when, for example, it is prepared as an aqueous or organic solvent mold-releasing agent having a concentration of about 1.0 wt. % or less, and when it is applied to an object to be subjected to a mold release treatment (e.g., a molding mold). This excellent effect is attributable to the extremely high solubility of the polyfluoroalkylphosphonic acid (salt) and oxyalkylene ester thereof in solvents. Using this as an active ingredient, a mold-releasing agent having excellent mold releasability can be obtained.

By combining use of the polyfluoroalkylphosphonic acid (salt) and oxyalkylene ester thereof, the mold-releasing agent has a synergistic effect on improving mold releasability and mold release life. Moreover, since this mold-releasing agent exhibits excellent mold releasability and durability, mold contamination caused by the mold-releasing agent can be reduced, and the dimensional accuracy of the molded product can be improved.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

The polyfluoroalkylphosphonic acid, which is used as one active ingredient of the mold-releasing agent, is represented by the general formula:

C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(C)P(O)(OH)₂  [I]

The polyfluoroalkylphosphonic acid oxyalkylene ester represented by the general formula:

C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)[O(RO)_(m)R′]_(d)(OH)_(2-d)  [XI]

which is used as the other active ingredient, is produced by subjecting a polyfluoroalkylphosphonic acid (which is not necessarily the same as the polyfluoroalkylphosphonic acid [I]) and a polyalkyleneglycol or a monoether thereof represented by the general formula:

HO(RO)_(m)R′  [X]

to a condensation reaction.

The polyfluoroalkylphosphonic acid of the formula:

C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(C)P(O)(OH)₂  [I]

is produced by the hydrolysis reaction of a polyfluoroalkylphosphonic acid diester represented by the general formula:

C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)(OR)₂  [II]

wherein R is an alkyl group having 1 to 4 carbon atoms, n is an integer of 1 to 6, a is an integer of 1 to 4, b is an integer of 1 to 3, and c is an integer of 1 to 3.

The polyfluoroalkylphosphonic acid diester [II], which is used as a starting material for this reaction, is obtained by the reaction of a polyfluoroalkyl iodide [III] of the formula:

C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)I  [III]

with trialkyl phosphite P(OR)₃. The polyfluoroalkyl iodide [III] is a known compound and is disclosed in Patent Document 8.

The polyfluoroalkyl iodide [III], which is used as a starting material for the synthesis of the polyfluoroalkylphosphonic acid diester [II], is produced by the addition reaction of a terminally iodized compound represented by the general formula:

C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)I  [IV]

with ethylene. The ethylene addition reaction is carried out in such a manner that the compound [IV] is subjected to an addition reaction with pressurized ethylene in the presence of a peroxide initiator. The number of addition is 1 to 3, preferably 1, although depending on the reaction conditions. Although the reaction temperature depends on the degradation temperature of the initiator used, the reaction is generally conducted at about 80 to 120° C.; when a peroxide initiator that decomposes at a low temperature is used, the reaction can be conducted at 80° C. or below.

As a peroxide initiator, tert-butyl peroxide, di(tert-butylcyclohexyl)peroxy dicarbonate, dicetylperoxy dicarbonate, di-n-propylperoxy dicarbonate, diisopropylperoxy dicarbonate, di-sec-butylperoxy dicarbonate, or the like may be used at a ratio of about 1 to 5 mol % with respect to the compound [IV], in terms of the progress and controllability of the reaction.

The terminally iodized compound [IV] is synthesized through a series of the following steps:

(1) A perfluoroalkyl iodide represented by the general formula:

C_(n)F_(2n+1)I (n: 1 to 6)

is reacted with vinylidene fluoride in the presence of a peroxide initiator as described above in an amount of about 0.1 to 0.5 mol % based on the starting material compound to obtain a compound represented by the general formula:

C_(n)F_(2n+1)(CH₂CF₂)_(a)I  [V]

(2). The compound represented by the general formula [V] is reacted with tetrafluoroethylene in the presence of a peroxide initiator to thereby obtain a terminally iodized compound represented by the general formula [IV] described above. In the general formula [IV], b is an integer of 1 to 3, preferably 1 or 2. The organic peroxide initiator as mentioned above can be used in this reaction in the same amount as in step (1).

Although the reaction temperature of the addition reaction of vinylidene fluoride and tetrafluoroethylene depends on the decomposition temperature of the initiator used, the use of a peroxide initiator that decomposes at a low temperature allows the reaction to occur at 80° C. or less under low-pressure conditions. The reaction is carried out in the following manner. The perfluoroalkyl iodide C_(n)F₂₊₁I or the compound [V] is charged in an autoclave, and the internal temperature is increased to about 10 to 60° C. For example, when the temperature reaches 50° C., a peroxide initiator dissolved in the perfluoroalkyl iodide C_(n)F_(2n+1)I or the compound [V] is added thereto. When the internal temperature reaches 55° C., for example, vinylidene fluoride or tetrafluoroethylene is added in batches while maintaining the pressure at about 0.1 to 0.6 MPa. After the desired amount of vinylidene fluoride or tetrafluoroethylene is added in batches, aging is carried out, for example, at a temperature of about 55 to 80° C. for about one hour. The amount of vinylidene fluoride or tetrafluoroethylene added affects the number of vinylidene fluoride skeletons a or tetrafluoroethylene skeletons b added by the reaction. Generally, a mixture of various a values and b values is formed.

The fact that these reactions can be carried out at low temperatures indicates that not only energy usage amount can be reduced, but also corrosion due to hydrofluoric acid etc. in facilities can be prevented, thereby reducing the frequency of updating the facilities. Additionally, since more inexpensive materials can be used, capital investment costs can also be kept low, in addition to the decrease in update frequency.

Specific examples of the compound [IV] to which ethylene is added include the following compounds. These compounds are mixtures of oligomers having various a values and b values. Oligomers that have specific a value and b value can be isolated by distilling the mixtures. Oligomers that do not have predetermined a and b values can be reused after isolation or as the mixtures in the reaction of increasing the number of oligomers with vinylidene fluoride or tetrafluoroethylene.

C₂F₅(CH₂CF₂)(CF₂CF₂)I

C₂F₅(CH₂CF₂)(CF₂CF₂)₂I

C₂F₅(CH₂CF₂)₂(CF₂CF₂)I

C₂F₅(CH₂CF₂)₂(CF₂CF₂)₂I

C₄F₉(CH₂CF₂)(CF₂CF₂)I

C₄F₉(CH₂CF₂)₂(CF₂CF₂)I

C₄F₉(CH₂CF₂)(CF₂CF₂)₂I

C₄F₉(CH₂CF₂)₂(CF₂CF₂)₂I

C₂F₅(CH₂CF₂)(CF₂CF₂)₃I

C₄F₉(CH₂CF₂)(CF₂CF₂)₃I

The polyfluoroalkyl iodide [III] prepared by the addition reaction of the compound [IV] as described above with ethylene can be reacted with trialkyl phosphite P(OR)₃ having an alkyl group containing 1 to 4 carbon atoms, such as trimethyl phosphite, triethyl phosphite, tripropyl phosphite, or tributyl phosphite, to perform the RI-elimination reaction, thereby obtaining a polyfluoroalkylphosphonic acid diester [II], which is used as a starting material. Without the addition reaction of the compound [IV] with ethylene, the RI-elimination reaction with trialkyl phosphite does not proceed.

The hydrolysis reaction of the polyfluoroalkylphosphonic acid diester [II] can be readily carried out by stirring at about 90 to 100° C. in the presence of an acid catalyst, such as inorganic acid typified by concentrated hydrochloric acid. The resulting reaction mixture is filtered under reduced pressure, followed by water washing/filtration, acetone washing/filtration, and other methods, thereby obtaining a polyfluoroalkylphosphonic acid [I], which is used as one reaction starting material, with a good yield of 90% or more.

The obtained polyfluoroalkylphosphonic acid [I] can also be used in the form of a salt after neutralization. The salt is generally formed by titration with a salt-forming reactant, such as sodium hydroxide, ammonium hydroxide, zinc sulfate, zinc acetate, zinc oxide, triethylamine, morpholine, triethanolamine, or tris(2-hydroxyethyl)amine, while identifying the equivalence point from the pH level, to obtain an acidic mono-, di- or tri-valent metal salt, amine salt, or ammonium salt. Examples of polyfluoroalkylphosphonic acid salts to be obtained include sodium, potassium, lithium, barium, magnesium, calcium, zinc, and other metal salts; ammonium salts; ammonium salts substituted by alkyl groups or cycloalkyl groups, such as monoethyl, monoisopropyl, diethyl, dicyclohexyl, and triethyl; ammonium salts substituted by hydroxyalkyl groups, such as monoethanol, diethanol, triethanol, and diisopropanol; and the like, of polyfluoroalkylphosphonic acids.

Examples of the polyalkyleneglycol or monoether thereof represented the general formula:

HO(RO)_(m)R′  [X]

which is used as the other reaction starting material, include polyethyleneglycol, polypropyleneglycol, polybutyleneglycol, polyhexyleneglycol, or monoalkyl ether or monoaralkyl ether thereof; preferably, monomethyl ether, monoethyl ether, etc., wherein m is 1 to 100, and the number average molecular weight (Mn) is preferably about 200 to 4,000, are used.

The condensation reaction between the polyfluoroalkylphosphonic acid [I] and the polyalkyleneglycol or monoether thereof [X] is carried out by heating at a temperature of about 80 to 180° C. using a dehydration catalyst, such as concentrated sulfuric acid or concentrated hydrochloric acid. In the reaction, for example, nitrogen bubbling is continuously performed to remove produced water from the reaction system, thereby promoting the dehydration-condensation reaction.

The reaction mixture comprises about 50 wt. % of unreacted polyalkyleneglycol (monoether) and about 50 wt. % of reaction product. The reaction product comprises a mixture of a polyfluoroalkylphosphonic acid monooxyalkylene ester [A] represented by the general formula:

C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)[O(RO)_(m)R′](OH)

and a polyfluoroalkylphosphonic acid bis(oxyalkylene)ester [B] represented by the general formula:

C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(C)P(O) [O(RO)_(m)R′]₂

The polyalkyleneglycol (monoether) [X] is used in an equimolar amount or more based on the polyfluoroalkylphosphonic acid [I]. When the molar ratio is about 2, generally about 1.5 to 2.5, the monooxyalkylene ester [A] is mainly produced; and when the molar ratio is about 4, generally about 3.0 to 4.5, the bis(oxyalkylene)ester [B] is mainly produced.

When a polyalkyleneglycol that is not monoetherified is used, the monooxyalkylene ester [A] or bis(oxyalkylene)ester [B] is mainly produced as well, depending on the molar ratio used. At the same time, a small amount of a product [C] of the following formula in which a polyfluoroalkylphosphonic acid is added by condensation to each of the glycol groups at both ends is also produced.

C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)(OH)—O(RO)_(m)—P(O)(OH)—(CH₂CH₂)_(c)(CF₂CF₂)_(b)(CF₂CH₂)_(a)C_(n)F_(2n+1)

The separation of each of the unreacted polyalkyleneglycol (monoether), polyfluoroalkylphosphonic acid monooxyalkylene ester, and polyfluoroalkylphosphonic acid bis(oxyalkylene)ester from the reaction mixture is performed using preparative liquid chromatography; however, the reaction mixture containing the unreacted polyalkyleneglycol (monoether) can be used as it is in the preparation of mold-releasing agents. Since the unreacted polyalkyleneglycol (monoether) has the effect of reducing the surface tension of water and improving wettability, there is no need to remove the unreacted polyalkyleneglycol (monoether).

The preparation of a mold-releasing agent using the polyfluoroalkylphosphonic acid [I] and the polyfluoroalkylphosphonic acid oxyalkylene ester [XI] obtained as above is performed using the polyfluoroalkylphosphonic acid [I] and the polyfluoroalkylphosphonic acid oxyalkylene ester [XI] at a weight ratio of 1 to 99:99 to 1, preferably 20 to 90:80 to 10 (wherein the weight of [XI] does not include the weight of unreacted polyalkyleneglycol or monoether thereof), and by dilution with water or an organic solvent to form an aqueous solution, aqueous dispersion, or organic solvent solution in which the mixture of [I] and [XI] has a solid matters concentration of about 0.01 to 30 wt. %, preferably about 0.05 to 3 wt. %.

An example of usable organic solvents is at least one of alcohols, such as methanol, ethanol, n-propanol, and isopropanol; ketones, such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ethers, such as diethyl ether, diisopropyl ether, dioxane, and tetrahydrofuran; esters, such as ethyl acetate and butyl acetate; polyols or ethers thereof, such as ethyleneglycol, propyleneglycol, diethyleneglycol, triethyleneglycol, tetraethyleneglycol, dipropyleneglycol, tripropyleneglycol, tetrapropyleneglycol, diethyleneglycol monomethyl ether, dipropyleneglycol monomethyl ether, tripropyleneglycol monomethyl ether, and glycerin; polyvalent alcohol derivatives, such as methyl cellosolve, ethyl cellosolve, methyl carbitol, and ethyl carbitol; halogenated hydrocarbons, such as carbon tetrachloride, methylene chloride, trichloroethylene, perchloroethylene, trichloroethane, trichlorofluoromethane, tetrachlorodifluoroethane, trichlorotrifluoroethane, and 1,4-bis(trifluoromethyl)benzene; and the like. Here, the organic solvent can be used in combination with water.

Other than the above amine neutralizers, the mold-releasing agent solution may contain, if necessary, various ionic and non-ionic surfactants for improving the wettability of the mold-releasing agent; silicone oil, silicone varnish, etc., for further improving mold releasability and lubricity.

The mold-releasing agent solution can be applied to a mold by any common method, such as dipping, spraying, brushing, aerosol spraying, or impregnated fabric coating. Moreover, examples of molding materials to be molded with a mold to which the mold-releasing agent is applied include polyurethane, polycarbonate, epoxy resin, phenol resin, polyimide resin, vinyl chloride resin, and other resins; natural rubber, chloroprene rubber, fluororubber, and other rubbers.

EXAMPLES

The following describes the present invention with reference to Examples.

Reference Example 1

(1) In a 1-L, four-necked flask equipped with a thermometer and a receiver for removing low-boiling substances, 500 g (0.92 mol) of a compound of the formula:

C₄F₉(CH₂CF₂)(CF₂CF₂)(CH₂CH₂)I (99 GC %)

and 213 g (1.84 mol) of triethyl phosphite P(OC₂H₅)₃ were charged, and the mixture was stirred at 155° C. At this time, to remove the by-product, i.e., ethyl iodide, from the reaction system, nitrogen gas was bubbled into the reaction solution using a small tube. A slight amount of reaction solution was taken and subjected to gas chromatographic analysis to confirm the remaining amount of triethyl phosphite. Thereafter, triethyl phosphite was further added in four batches in an amount of 107 g (0.92 mol) per batch, and the mixture was stirred for 18 hours in total.

After the reaction was completed, the reaction mixture was subjected to simple distillation under reduced pressure at an internal pressure of 0.2 kPa, an internal temperature of 145 to 155° C., and an overhead temperature of 138 to 142° C. The distillate fraction was washed with water, thereby obtaining 407 g (yield: 79%) of a purified reaction product (98 GC %).

The results of ¹H-NMR and ¹⁹F-NMR confirmed that the resulting purified reaction product was a compound represented by the following formula:

C₄F₉(CH₂CF₂)(CF₂CF₂)(CH₂CH₂)P(O)OCH₂CH₃)₂

(2) In a 1-L, four-necked flask equipped with a thermometer and a condenser, 300 g (0.53 mol) of the obtained phosphonic acid diester of the formula:

C₄F₉(CH₂CF₂)(CF₂CF₂)(CH₂CH₂)P(O)(OCH₂CH₃)₂ (96 GC %)

and 300 g of about 35% concentrated hydrochloric acid were charged, and the mixture was stirred at 100° C. for 12 hours. After cooling, filtration under reduced pressure was performed to thereby collect 287 g of solid matters. The solid matters were washed with water and filtrated again, further followed by acetone washing and filtration, thereby obtaining 240 g (0.49 mol; yield: 93%) of the target product.

The results of ¹H-NMR and ¹⁹F-NMR confirmed that the resulting product was the target compound (polyfluoroalkylphosphonic acid A; MW: 492, F content: 57.9 wt. %) represented by the following formula:

C₄F₉(CH₂CF₂)(CF₂CF₂)(CH₂CH₂)P(O)(OH)₂

(3) In a 500-ml reaction vessel equipped with a stirrer, a nitrogen bubbling device, and a thermometer, 99 g (0.20 mol) of the polyfluoroalkylphosphonic acid A obtained in Reference Example 1 (2) and 201 g (0.40 mol) of polyethyleneglycol monomethyl ether [PEG-a] (Uniox M-550, produced by NOF Corporation; MW=496, m=about 12) of the formula:

HO(CH₂CH₂O)_(m)CH₃

were charged. After the temperature was raised to 70° C., nitrogen bubbling was performed. Thereafter, the internal temperature of the reaction vessel was raised to 155° C., and 1.2 g of concentrated sulfuric acid was added. The reaction was continued for 48 hours while the water produced by the reaction was removed from the reaction system by continuing nitrogen bubbling in the ongoing reaction.

The obtained reaction mixture was isolated by preparative liquid chromatography, and the composition of the isolated product was confirmed by ¹⁹F-NMR and ¹H-NMR. As a result, the weight ratio of PEG-a, product Ia, and product Ib was 50/47/3.

Product Ia (m=about 12):

C₄F₉(CH₂CF₂)(CF₂CF₂)(CH₂CH₂)P(O)[O(CH₂CH₂O)_(m)CH₃](OH)

Product Ib (m=about 12):

C₄F₉(CH₂CF₂)(CF₂CF₂)(CH₂CH₂)P(O)[O(CH₂CH₂O)_(m)CH₃]₂

Reference Example 2

(1) In a 1-L, four-necked flask equipped with a thermometer and a receiver for removing low-boiling substances, 500 g (0.90 mol) of a compound of the formula:

C₂F₅(CH₂CF₂)(CF₂CF₂)₂(CH₂CH₂)I (97 GC %)

and 208 g (1.80 mol) of triethyl phosphite P(OC₂H₅)₃ were charged, and the mixture was stirred at 155° C. At this time, to remove the by-product, i.e., ethyl iodide, from the reaction system, nitrogen gas was bubbled into the reaction solution using a small tube. A slight amount of reaction solution was taken and subjected to gas chromatographic analysis to confirm the remaining amount of triethyl phosphite. Thereafter, triethyl phosphite was further added in four batches in an amount of 104 g (0.90 mol) per batch, and the mixture was stirred for 18 hours in total.

After the reaction was completed, the reaction mixture was subjected to simple distillation under reduced pressure at an internal pressure of 0.2 kPa, an internal temperature of 145 to 155° C., and an overhead temperature of 138 to 141° C. The distillate fraction was washed with water, thereby obtaining 397 g (yield: 78%) of a purified reaction product (97 GC %).

The results of ¹H-NMR and ¹⁹F-NMR confirmed that the resulting purified reaction product was a compound represented by the following formula:

C₂F₅(CH₂CF₂)(CF₂CF₂)₂(CH₂CH₂)P(O)(OCH₂CH₃)₂

(2) In a 1-L, four-necked flask equipped with a thermometer and a condenser, 300 g (0.52 mol) of the obtained phosphonic acid diester of the formula:

C₂F₅(CH₂CF₂)(CF₂CF₂)₂(CH₂CH₂)P(O)(OCH₂CH₃)₂ (95 GC %)

and 300 g of about 35% concentrated hydrochloric acid were charged, and the mixture was stirred at 100° C. for 12 hours. After cooling, filtration under reduced pressure was performed to thereby collect 271 g of solid matters. The solid matters were washed with water and filtrated again, further followed by acetone washing and filtration, thereby obtaining 235 g (0.48 mol; yield: 92%) of the target product.

The results of ¹H-NMR and ¹⁹F-NMR confirmed that the resulting product was the target compound (polyfluoroalkylphosphonic acid B; MW: 492, F content: 57.9 wt. %) represented by the following formula:

C₂F₅(CH₂CF₂)(CF₂CF₂)₂(CH₂CH₂)P(O)(OH)₂

(3) In Reference Example 1 (3), 99 g (0.20 mol) of the polyfluoroalkylphosphonic acid B obtained in above-mentioned (2) and 201 g (0.40 mol) of PEG-a were used, thereby obtaining 276 g (recovery rate: 92%) of a light yellow wax-like reaction mixture (F content: 18.8 wt. %).

The obtained reaction mixture was isolated by preparative liquid chromatography, and the composition of the isolated product was confirmed by ¹⁹F-NMR and ¹H-NMR. As a result, the weight ratio of PEG-a, product IIa, and product IIb was 50/47/3.

Product IIa (m=about 12):

C₂F₅(CH₂CF₂)(CF₂CF₂)₂(CH₂CH₂)P(O)[O(CH₂CH₂O)_(m)CH₃](OH)

Product IIb (m=about 12):

C₂F₅(CH₂CF₂)(CF₂CF₂)₂(CH₂CH₂)P(O)[O(CH₂CH₂O)_(m)CH₃]₂

Example 1

A mold-releasing agent aqueous solution comprising 0.2 wt. % of the polyfluoroalkylphosphonic acid A obtained in Reference Example 1 (2), 0.3 wt. % of the polyfluoroalkylphosphonic acid oxyalkylene ester-containing reaction mixture (containing unreacted PEG-a) obtained in Example 1 (3), 99.4 wt. % of ion exchange water, and 0.1 wt. % of triethylamine was prepared. Using the mold-releasing agent aqueous solution, mold releasability was evaluated by the following two measurement methods. The results were such that the mold releasability was 0.1 N, and the mold release life was 26 times.

<Evaluation of Mold Releasability and Mold Release Life>

Polyurethane prepolymer (100 parts by weight; Coronate C-4090, manufactured by Nippon Polyurethane Industry Co., Ltd.), which had been heated to 80° C., and 12.8 parts by weight of methylene-bis-o-chloroaniline curing agent (Iharacuamine MT, manufactured by Ihara Chemical Industry Co., Ltd.), which had been heat-melted, were mixed by stirring without forming air bubbles. The mixture was poured into an aluminum mold (diameter: 45 mm, depth: 50 mm) to which the above mold-releasing agent aqueous solution had been applied by spraying, and which had been preheated to 80° C. A hook was stood in the center of the space of the mold for removing the cured molded product. After heat-curing at 120° C. for 1 hour, the molded product was taken out from the mold by pulling the hook. The mold release load required to pull the hook was regarded as mold releasability. After the mold releasability was thus determined, mold release life was determined by measuring how many times a one-time application of the mold-releasing agent aqueous solution allowed mold releasing at a mold release load of 50 N or less.

Example 2

In Example 1, the amount of polyfluoroalkylphosphonic acid A was changed to 0.4 wt. %, the amount of polyfluoroalkylphosphonic acid oxyalkylene ester-containing reaction mixture was changed to 0.1 wt. %, the amount of ion exchange water was changed to 99.3 wt. %, and the amount of triethylamine was changed to 0.2 wt. %.

Example 3

In Example 1, the amount of ion exchange water was changed to 85.0 wt. %, and 14.4 wt. % of ethanol was used together with ion exchange water.

Example 4

In Example 1, the same amount (0.2 wt. %) of polyfluoroalkylphosphonic acid B was used in place of the polyfluoroalkylphosphonic acid A.

Comparative Example 1

In Example 1, the polyfluoroalkylphosphonic acid A was not used, the amount of polyfluoroalkylphosphonic acid oxyalkylene ester-containing reaction mixture was changed to 0.5 wt. %, the amount of ion exchange water was changed to 99.45 wt. %, and the amount of triethylamine was changed to 0.05 wt. %.

Comparative Example 2

In Example 3, the polyfluoroalkylphosphonic acid A was not used, the amount of polyfluoroalkylphosphonic acid oxyalkylene ester-containing reaction mixture was changed to 0.5 wt. %, the amount of ethanol was changed to 14.45 wt. %, and the amount of triethylamine was changed to 0.05 wt. %.

Comparative Example 3

In Example 1, the polyfluoroalkylphosphonic acid oxyalkylene ester-containing reaction mixture was not used, the amount of polyfluoroalkylphosphonic acid A was changed to 0.5 wt. %, the amount of ion exchange water was changed to 99.35 wt. %, and the amount of triethylamine was changed to 0.15 wt. %.

The following table shows the results obtained in the Examples and Comparative Examples above, together with the amount of each component of the mold-releasing agent aqueous solution (unit: wt. %).

TABLE Example Comp. Ex. 1 2 3 4 1 2 3 [Mold-releasing agent aqueous solution] Phosphonic acid A 0.2 0.4 0.2 — — — 0.5 Phosphonic acid B — — — 0.2 — — — Phosphonic acid ester- 0.3 0.1 0.3 0.3 0.5 0.5 — containing reaction mixture Ion exchange water 99.4 99.3 85.0 99.4 99.45 85.0 99.35 Ethanol — — 14.4 — — 14.45 — Triethylamine 0.1 0.2 0.1 0.1 0.05 0.05 0.15 [Measurement result] Mold releasability (N) 0.1 0.1 0.1 0.2 4.5 5.0 14.0 Mold release life 26 24 25 20 10 11 9 (time) 

1. A mold-releasing agent comprising as active ingredients, a polyfluoroalkylphosphonic acid represented by the general formula: C_(n)F_(2n+1) (CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)(OH)₂  [I] wherein n is an integer of 1 to 6, a is an integer of 1 to 4, b is an integer of 1 to 3, c is an integer of 1 to 3, or a salt thereof and a polyfluoroalkylphosphonic acid oxyalkylene ester represented by the general formula: C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)[O(RO)_(m)R′]_(d)(OH)_(2-d)  [XI] wherein RO is a linear or branched oxyalkylene group having 2 to 6 carbon atoms, R′ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or aralkyl group, n is an integer of 1 to 6, a is an integer of 1 to 4, b is an integer of 1 to 3, c is an integer of 1 to 3, d is an integer of 1 or 2, and m is an integer of 1 to
 100. 2. The mold-release agent according to claim 1, wherein a polyfluoroalkylphosphonic acid monooxyalkylene ester represented by the general formula: C_(n)F_(2n+1) (CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)[O(RO)_(m)R′](OH) and a polyfluoroalkylphosphonic acid bis(oxyalkylene)ester represented by the formula: C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)[O(RO)_(m)R′]₂ are used as a mixture of the polyfluoroalkylphosphonic acid oxyalkylene ester.
 3. The mold-releasing agent according to claim 1, further containing a polyalkyleneglycol or monoether thereof.
 4. The mold-releasing agent according to claim 1, which is used as an aqueous solution.
 5. The mold-releasing agent according to claim 1, which is used as an aqueous dispersion.
 6. The mold-releasing agent according to claim 1, which is used as an organic solvent solution.
 7. The mold-releasing agent according to claim 1, wherein the polyfluoroalkylphosphonic acid oxyalkylene ester thereof have a solid matters content of 0.01 to 30 wt. %.
 8. The mold-releasing agent according to claim 1, which is applied to a molding mold for use.
 9. The mold-releasing agent according to claim 2, further containing a polyalkyleneglycol or monoether thereof.
 10. The mold-releasing agent according to claim 2, which is used as an aqueous solution.
 11. The mold-releasing agent according to claim 2, which is used as an aqueous dispersion.
 12. The mold-releasing agent according to claim 2, which is used as an organic solvent solution.
 13. The mold-releasing agent according to claim 2, wherein the polyfluoroalkylphosphonic acid oxyalkylene ester thereof have a solid matters content of 0.01 to 30 wt. %.
 14. The mold-releasing agent according to claim 2, which is applied to a molding mold for use. 